Hey Gambler, I see from your sig that you want audio overhaul. Here's a list of what I did.
I have the 4-channel and new JBL amp stuffed in center console with no overheat probs and no special ventilation. (knock on wood)
The JBL is pretty good sized, see link for spec dimensions.
Here's a list of the final hardware. Most of it I transferred from prior 01 Yukon then 03 Denali, now 07 Tahoe, so I've definitely got my money's worth out of the equipment. It pays to hang on stock stuff for the "deinstall"
4-Channel Amp:
Link to legacy area of Xtant (config'd with high level inputs from factory NAV unit):
http://www.xtant.com/archives/html/products/xtant4.4.cfm
JBL 700 Mono Amp:
Just upgraded 2 months ago.
http://www.jbl.com/car/products/product_detail.aspx?prod=GTO7001
Sub: Boston Pro 10.54:
Legacy status, link below is for the manual.
http://www.bostonacoustics.com/manuals/CarSubMan.pdf
Front Separates: Boston Pro 6.5s. Tweeter moved up to Bose front pillers
Legacy status, link below is replacement
http://www.bostonacoustics.com/car/car_product.aspx?category_id=14&family_id=20&product_id=296
Back Door: Boston Pro 6.5s. Mounted standard 2 way config same as above.
Coming this Saturday: Losing the ipod lockpick (works but kind of buggy) and having Peripheral's PXAMG Ipod/Audio gateway with HD Radio auxiliary module (HDRT) installed. Stay tuned for the results!!!!